Sharp R-9370 Service Manual page 20

R-9370
INDICATOR CIRCUIT
Method of Display
Indicator element is Fluorescent Display.
Basically, a Fluorescent Display is a triode having a cathode,
a grid and an anode. Usually, the cathode of Fluorescent Dis-
play is directly heated and the filament serves as cathode.
When a proper voltage is applied to the filament to heat it,
thermo-electrons are emitted and, with positive voltage with
respect to filament being applied to the anode and grid, elec-
trons hit against the anode to illuminate the fluorescent body.
If the anode or grid voltage is zero or negative against the fila-
ment, thermo-electrons can not reach the anode, hence the
fluorescent body is not luminescent.
In this model, the Fluorescent Display B-digits, 13-segments
are used for displaying figures.
The Fluorescent Display employs the dynamic drive method,
when the high level of anode signal and grid signal agree, the
corresponding segment displays.
The foliowng signals are responstble for speclfylng segments
I
Segment
1 sgnai / Segment I Sgnal /
Character format Its/-E-~ kE+G.
Indl-
MED
P43
M-HIGH
P43
HIGH P43
COMPCl
WI3
AUTO
PW
Kg Pm
COOK
PSI I
Digure T-l 1. Indicator Circuit
19